The goal of this study is to reduce Hepatitis C Virus (HCV) seroincidence among recently initiated (less than 5 years) injection drug users (IDUs). New injectors are at high risk for bloodborne viral infections during their first years of injecting when they are least likely to seek formal substance abuse treatment and are likely to be practicing risky drug-use behaviors. In this study, 347 out-of-treatment IDUs will be recruited using Respondent Driven Sampling in Providence, Rhode Island. The Primary Aim of the present application is: To test if a brief Motivational Intervention (MI) will reduce the cumulative incidence of HCV compared to an "assessment only" condition using a randomized trial design. The Secondary Aims are: 1) to test the mechanism through which the effect of brief MI occurs, and to determine the extent to which readiness to change risk behaviors is associated with reduction in HCV incidence; 2) to describe specific patient characteristics associated with reduction in HCV risk behaviors; 3) to describe time trends in HCV risk behaviors across the two groups over the 24-month period. The occurrence of injection drug use in a population with traditionally poor linkage to primary care, an enormous burden of illness, and high HCV and other bloodborne pathogen transmission risk, compels health care providers and policymakers to explore innovative approaches to improve the health of this group. This proposal further develops a brief motivational risk reduction strategy for IDUs previously demonstrated by these investigators to reduce HIV risk behaviors, applies it to HCV risk behaviors, and uses biological outcomes to test efficacy of our approach.